drivers/input/touchscreen/wm831x-ts.c

   1 /*
   2  * Touchscreen driver for WM831x PMICs
   3  *
   4  * Copyright 2011 Wolfson Microelectronics plc.
   5  * Author: Mark Brown <broonie@opensource.wolfsonmicro.com>
   6  *
   7  * This program is free software; you can redistribute  it and/or modify it
   8  * under  the terms of  the GNU General  Public License as published by the
   9  * Free Software Foundation;  either version 2 of the  License, or (at your
  10  * option) any later version.
  11  */
  12
  13 #include <linux/module.h>
  14 #include <linux/moduleparam.h>
  15 #include <linux/kernel.h>
  16 #include <linux/string.h>
  17 #include <linux/pm.h>
  18 #include <linux/input.h>
  19 #include <linux/interrupt.h>
  20 #include <linux/io.h>
  21 #include <linux/mfd/wm831x/core.h>
  22 #include <linux/mfd/wm831x/irq.h>
  23 #include <linux/mfd/wm831x/pdata.h>
  24 #include <linux/platform_device.h>
  25 #include <linux/slab.h>
  26 #include <linux/types.h>
  27
  28 /*
  29  * R16424 (0x4028) - Touch Control 1
  30  */
  31 #define WM831X_TCH_ENA                          0x8000  /* TCH_ENA */
  32 #define WM831X_TCH_CVT_ENA                      0x4000  /* TCH_CVT_ENA */
  33 #define WM831X_TCH_SLPENA                       0x1000  /* TCH_SLPENA */
  34 #define WM831X_TCH_Z_ENA                        0x0400  /* TCH_Z_ENA */
  35 #define WM831X_TCH_Y_ENA                        0x0200  /* TCH_Y_ENA */
  36 #define WM831X_TCH_X_ENA                        0x0100  /* TCH_X_ENA */
  37 #define WM831X_TCH_DELAY_MASK                   0x00E0  /* TCH_DELAY - [7:5] */
  38 #define WM831X_TCH_DELAY_SHIFT                       5  /* TCH_DELAY - [7:5] */
  39 #define WM831X_TCH_DELAY_WIDTH                       3  /* TCH_DELAY - [7:5] */
  40 #define WM831X_TCH_RATE_MASK                    0x001F  /* TCH_RATE - [4:0] */
  41 #define WM831X_TCH_RATE_SHIFT                        0  /* TCH_RATE - [4:0] */
  42 #define WM831X_TCH_RATE_WIDTH                        5  /* TCH_RATE - [4:0] */
  43
  44 /*
  45  * R16425 (0x4029) - Touch Control 2
  46  */
  47 #define WM831X_TCH_PD_WK                        0x2000  /* TCH_PD_WK */
  48 #define WM831X_TCH_5WIRE                        0x1000  /* TCH_5WIRE */
  49 #define WM831X_TCH_PDONLY                       0x0800  /* TCH_PDONLY */
  50 #define WM831X_TCH_ISEL                         0x0100  /* TCH_ISEL */
  51 #define WM831X_TCH_RPU_MASK                     0x000F  /* TCH_RPU - [3:0] */
  52 #define WM831X_TCH_RPU_SHIFT                         0  /* TCH_RPU - [3:0] */
  53 #define WM831X_TCH_RPU_WIDTH                         4  /* TCH_RPU - [3:0] */
  54
  55 /*
  56  * R16426-8 (0x402A-C) - Touch Data X/Y/X
  57  */
  58 #define WM831X_TCH_PD                           0x8000  /* TCH_PD1 */
  59 #define WM831X_TCH_DATA_MASK                    0x0FFF  /* TCH_DATA - [11:0] */
  60 #define WM831X_TCH_DATA_SHIFT                        0  /* TCH_DATA - [11:0] */
  61 #define WM831X_TCH_DATA_WIDTH                       12  /* TCH_DATA - [11:0] */
  62
  63 struct wm831x_ts {
  64         struct input_dev *input_dev;
  65         struct wm831x *wm831x;
  66         unsigned int data_irq;
  67         unsigned int pd_irq;
  68         bool pressure;
  69         bool pen_down;
  70         struct work_struct pd_data_work;
  71 };
  72
  73 static void wm831x_pd_data_work(struct work_struct *work)
  74 {
  75         struct wm831x_ts *wm831x_ts =
  76                 container_of(work, struct wm831x_ts, pd_data_work);
  77
  78         if (wm831x_ts->pen_down) {
  79                 enable_irq(wm831x_ts->data_irq);
  80                 dev_dbg(wm831x_ts->wm831x->dev, "IRQ PD->DATA done\n");
  81         } else {
  82                 enable_irq(wm831x_ts->pd_irq);
  83                 dev_dbg(wm831x_ts->wm831x->dev, "IRQ DATA->PD done\n");
  84         }
  85 }
  86
  87 static irqreturn_t wm831x_ts_data_irq(int irq, void *irq_data)
  88 {
  89         struct wm831x_ts *wm831x_ts = irq_data;
  90         struct wm831x *wm831x = wm831x_ts->wm831x;
  91         static int data_types[] = { ABS_X, ABS_Y, ABS_PRESSURE };
  92         u16 data[3];
  93         int count;
  94         int i, ret;
  95
  96         if (wm831x_ts->pressure)
  97                 count = 3;
  98         else
  99                 count = 2;
 100
 101         wm831x_set_bits(wm831x, WM831X_INTERRUPT_STATUS_1,
 102                         WM831X_TCHDATA_EINT, WM831X_TCHDATA_EINT);
 103
 104         ret = wm831x_bulk_read(wm831x, WM831X_TOUCH_DATA_X, count,
 105                                data);
 106         if (ret != 0) {
 107                 dev_err(wm831x->dev, "Failed to read touch data: %d\n",
 108                         ret);
 109                 return IRQ_NONE;
 110         }
 111
 112         /*
 113          * We get a pen down reading on every reading, report pen up if any
 114          * individual reading does so.
 115          */
 116         wm831x_ts->pen_down = true;
 117         for (i = 0; i < count; i++) {
 118                 if (!(data[i] & WM831X_TCH_PD)) {
 119                         wm831x_ts->pen_down = false;
 120                         continue;
 121                 }
 122                 input_report_abs(wm831x_ts->input_dev, data_types[i],
 123                                  data[i] & WM831X_TCH_DATA_MASK);
 124         }
 125
 126         if (!wm831x_ts->pen_down) {
 127                 /* Switch from data to pen down */
 128                 dev_dbg(wm831x->dev, "IRQ DATA->PD\n");
 129
 130                 disable_irq_nosync(wm831x_ts->data_irq);
 131
 132                 /* Don't need data any more */
 133                 wm831x_set_bits(wm831x, WM831X_TOUCH_CONTROL_1,
 134                                 WM831X_TCH_X_ENA | WM831X_TCH_Y_ENA |
 135                                 WM831X_TCH_Z_ENA, 0);
 136
 137                 /* Flush any final samples that arrived while reading */
 138                 wm831x_set_bits(wm831x, WM831X_INTERRUPT_STATUS_1,
 139                                 WM831X_TCHDATA_EINT, WM831X_TCHDATA_EINT);
 140
 141                 wm831x_bulk_read(wm831x, WM831X_TOUCH_DATA_X, count, data);
 142
 143                 if (wm831x_ts->pressure)
 144                         input_report_abs(wm831x_ts->input_dev,
 145                                          ABS_PRESSURE, 0);
 146
 147                 input_report_key(wm831x_ts->input_dev, BTN_TOUCH, 0);
 148
 149                 schedule_work(&wm831x_ts->pd_data_work);
 150         } else {
 151                 input_report_key(wm831x_ts->input_dev, BTN_TOUCH, 1);
 152         }
 153
 154         input_sync(wm831x_ts->input_dev);
 155
 156         return IRQ_HANDLED;
 157 }
 158
 159 static irqreturn_t wm831x_ts_pen_down_irq(int irq, void *irq_data)
 160 {
 161         struct wm831x_ts *wm831x_ts = irq_data;
 162         struct wm831x *wm831x = wm831x_ts->wm831x;
 163         int ena = 0;
 164
 165         if (wm831x_ts->pen_down)
 166                 return IRQ_HANDLED;
 167
 168         disable_irq_nosync(wm831x_ts->pd_irq);
 169
 170         /* Start collecting data */
 171         if (wm831x_ts->pressure)
 172                 ena |= WM831X_TCH_Z_ENA;
 173
 174         wm831x_set_bits(wm831x, WM831X_TOUCH_CONTROL_1,
 175                         WM831X_TCH_X_ENA | WM831X_TCH_Y_ENA | WM831X_TCH_Z_ENA,
 176                         WM831X_TCH_X_ENA | WM831X_TCH_Y_ENA | ena);
 177
 178         wm831x_set_bits(wm831x, WM831X_INTERRUPT_STATUS_1,
 179                         WM831X_TCHPD_EINT, WM831X_TCHPD_EINT);
 180
 181         wm831x_ts->pen_down = true;
 182
 183         /* Switch from pen down to data */
 184         dev_dbg(wm831x->dev, "IRQ PD->DATA\n");
 185         schedule_work(&wm831x_ts->pd_data_work);
 186
 187         return IRQ_HANDLED;
 188 }
 189
 190 static int wm831x_ts_input_open(struct input_dev *idev)
 191 {
 192         struct wm831x_ts *wm831x_ts = input_get_drvdata(idev);
 193         struct wm831x *wm831x = wm831x_ts->wm831x;
 194
 195         wm831x_set_bits(wm831x, WM831X_TOUCH_CONTROL_1,
 196                         WM831X_TCH_ENA | WM831X_TCH_CVT_ENA |
 197                         WM831X_TCH_X_ENA | WM831X_TCH_Y_ENA |
 198                         WM831X_TCH_Z_ENA, WM831X_TCH_ENA);
 199
 200         wm831x_set_bits(wm831x, WM831X_TOUCH_CONTROL_1,
 201                         WM831X_TCH_CVT_ENA, WM831X_TCH_CVT_ENA);
 202
 203         return 0;
 204 }
 205
 206 static void wm831x_ts_input_close(struct input_dev *idev)
 207 {
 208         struct wm831x_ts *wm831x_ts = input_get_drvdata(idev);
 209         struct wm831x *wm831x = wm831x_ts->wm831x;
 210
 211         /* Shut the controller down, disabling all other functionality too */
 212         wm831x_set_bits(wm831x, WM831X_TOUCH_CONTROL_1,
 213                         WM831X_TCH_ENA | WM831X_TCH_X_ENA |
 214                         WM831X_TCH_Y_ENA | WM831X_TCH_Z_ENA, 0);
 215
 216         /* Make sure any pending IRQs are done, the above will prevent
 217          * new ones firing.
 218          */
 219         synchronize_irq(wm831x_ts->data_irq);
 220         synchronize_irq(wm831x_ts->pd_irq);
 221
 222         /* Make sure the IRQ completion work is quiesced */
 223         flush_work(&wm831x_ts->pd_data_work);
 224
 225         /* If we ended up with the pen down then make sure we revert back
 226          * to pen detection state for the next time we start up.
 227          */
 228         if (wm831x_ts->pen_down) {
 229                 disable_irq(wm831x_ts->data_irq);
 230                 enable_irq(wm831x_ts->pd_irq);
 231                 wm831x_ts->pen_down = false;
 232         }
 233 }
 234
 235 static int wm831x_ts_probe(struct platform_device *pdev)
 236 {
 237         struct wm831x_ts *wm831x_ts;
 238         struct wm831x *wm831x = dev_get_drvdata(pdev->dev.parent);
 239         struct wm831x_pdata *core_pdata = dev_get_platdata(pdev->dev.parent);
 240         struct wm831x_touch_pdata *pdata = NULL;
 241         struct input_dev *input_dev;
 242         int error, irqf;
 243
 244         if (core_pdata)
 245                 pdata = core_pdata->touch;
 246
 247         wm831x_ts = devm_kzalloc(&pdev->dev, sizeof(struct wm831x_ts),
 248                                  GFP_KERNEL);
 249         input_dev = devm_input_allocate_device(&pdev->dev);
 250         if (!wm831x_ts || !input_dev) {
 251                 error = -ENOMEM;
 252                 goto err_alloc;
 253         }
 254
 255         wm831x_ts->wm831x = wm831x;
 256         wm831x_ts->input_dev = input_dev;
 257         INIT_WORK(&wm831x_ts->pd_data_work, wm831x_pd_data_work);
 258
 259         /*
 260          * If we have a direct IRQ use it, otherwise use the interrupt
 261          * from the WM831x IRQ controller.
 262          */
 263         wm831x_ts->data_irq = wm831x_irq(wm831x,
 264                                          platform_get_irq_byname(pdev,
 265                                                                  "TCHDATA"));
 266         if (pdata && pdata->data_irq)
 267                 wm831x_ts->data_irq = pdata->data_irq;
 268
 269         wm831x_ts->pd_irq = wm831x_irq(wm831x,
 270                                        platform_get_irq_byname(pdev, "TCHPD"));
 271         if (pdata && pdata->pd_irq)
 272                 wm831x_ts->pd_irq = pdata->pd_irq;
 273
 274         if (pdata)
 275                 wm831x_ts->pressure = pdata->pressure;
 276         else
 277                 wm831x_ts->pressure = true;
 278
 279         /* Five wire touchscreens can't report pressure */
 280         if (pdata && pdata->fivewire) {
 281                 wm831x_set_bits(wm831x, WM831X_TOUCH_CONTROL_2,
 282                                 WM831X_TCH_5WIRE, WM831X_TCH_5WIRE);
 283
 284                 /* Pressure measurements are not possible for five wire mode */
 285                 WARN_ON(pdata->pressure && pdata->fivewire);
 286                 wm831x_ts->pressure = false;
 287         } else {
 288                 wm831x_set_bits(wm831x, WM831X_TOUCH_CONTROL_2,
 289                                 WM831X_TCH_5WIRE, 0);
 290         }
 291
 292         if (pdata) {
 293                 switch (pdata->isel) {
 294                 default:
 295                         dev_err(&pdev->dev, "Unsupported ISEL setting: %d\n",
 296                                 pdata->isel);
 297                         /* Fall through */
 298                 case 200:
 299                 case 0:
 300                         wm831x_set_bits(wm831x, WM831X_TOUCH_CONTROL_2,
 301                                         WM831X_TCH_ISEL, 0);
 302                         break;
 303                 case 400:
 304                         wm831x_set_bits(wm831x, WM831X_TOUCH_CONTROL_2,
 305                                         WM831X_TCH_ISEL, WM831X_TCH_ISEL);
 306                         break;
 307                 }
 308         }
 309
 310         wm831x_set_bits(wm831x, WM831X_TOUCH_CONTROL_2,
 311                         WM831X_TCH_PDONLY, 0);
 312
 313         /* Default to 96 samples/sec */
 314         wm831x_set_bits(wm831x, WM831X_TOUCH_CONTROL_1,
 315                         WM831X_TCH_RATE_MASK, 6);
 316
 317         if (pdata && pdata->data_irqf)
 318                 irqf = pdata->data_irqf;
 319         else
 320                 irqf = IRQF_TRIGGER_HIGH;
 321
 322         error = request_threaded_irq(wm831x_ts->data_irq,
 323                                      NULL, wm831x_ts_data_irq,
 324                                      irqf | IRQF_ONESHOT,
 325                                      "Touchscreen data", wm831x_ts);
 326         if (error) {
 327                 dev_err(&pdev->dev, "Failed to request data IRQ %d: %d\n",
 328                         wm831x_ts->data_irq, error);
 329                 goto err_alloc;
 330         }
 331         disable_irq(wm831x_ts->data_irq);
 332
 333         if (pdata && pdata->pd_irqf)
 334                 irqf = pdata->pd_irqf;
 335         else
 336                 irqf = IRQF_TRIGGER_HIGH;
 337
 338         error = request_threaded_irq(wm831x_ts->pd_irq,
 339                                      NULL, wm831x_ts_pen_down_irq,
 340                                      irqf | IRQF_ONESHOT,
 341                                      "Touchscreen pen down", wm831x_ts);
 342         if (error) {
 343                 dev_err(&pdev->dev, "Failed to request pen down IRQ %d: %d\n",
 344                         wm831x_ts->pd_irq, error);
 345                 goto err_data_irq;
 346         }
 347
 348         /* set up touch configuration */
 349         input_dev->name = "WM831x touchscreen";
 350         input_dev->phys = "wm831x";
 351         input_dev->open = wm831x_ts_input_open;
 352         input_dev->close = wm831x_ts_input_close;
 353
 354         __set_bit(EV_ABS, input_dev->evbit);
 355         __set_bit(EV_KEY, input_dev->evbit);
 356         __set_bit(BTN_TOUCH, input_dev->keybit);
 357
 358         input_set_abs_params(input_dev, ABS_X, 0, 4095, 5, 0);
 359         input_set_abs_params(input_dev, ABS_Y, 0, 4095, 5, 0);
 360         if (wm831x_ts->pressure)
 361                 input_set_abs_params(input_dev, ABS_PRESSURE, 0, 4095, 5, 0);
 362
 363         input_set_drvdata(input_dev, wm831x_ts);
 364         input_dev->dev.parent = &pdev->dev;
 365
 366         error = input_register_device(input_dev);
 367         if (error)
 368                 goto err_pd_irq;
 369
 370         platform_set_drvdata(pdev, wm831x_ts);
 371         return 0;
 372
 373 err_pd_irq:
 374         free_irq(wm831x_ts->pd_irq, wm831x_ts);
 375 err_data_irq:
 376         free_irq(wm831x_ts->data_irq, wm831x_ts);
 377 err_alloc:
 378
 379         return error;
 380 }
 381
 382 static int wm831x_ts_remove(struct platform_device *pdev)
 383 {
 384         struct wm831x_ts *wm831x_ts = platform_get_drvdata(pdev);
 385
 386         free_irq(wm831x_ts->pd_irq, wm831x_ts);
 387         free_irq(wm831x_ts->data_irq, wm831x_ts);
 388
 389         return 0;
 390 }
 391
 392 static struct platform_driver wm831x_ts_driver = {
 393         .driver = {
 394                 .name = "wm831x-touch",
 395         },
 396         .probe = wm831x_ts_probe,
 397         .remove = wm831x_ts_remove,
 398 };
 399 module_platform_driver(wm831x_ts_driver);
 400
 401 /* Module information */
 402 MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
 403 MODULE_DESCRIPTION("WM831x PMIC touchscreen driver");
 404 MODULE_LICENSE("GPL");
 405 MODULE_ALIAS("platform:wm831x-touch");